The status report was developed on the basis of an assessment that was carried out in all countries of Central and Eastern Europe during May-July 2005. The assessment was based on a questionnaire developed by the REC in consultation with the UNEP Partnership for Clean Fuels and Vehicles (PCFV), US Environmental Protection Agency and the United Nations Department of Economic and Social Affairs (UNDESA). The questionnaire contained five main chapters: personal information, country-specific data, air quality, fuel quality and vehicle emissions.